Causes of Sludge

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To Me there is At least this:

Coke...Hard solid "dry" dirt like baked on
Sludge...Greasey thick stick goo.
Varnish...Baked on thin hard or sticky coating

I think that ALL are Oxidation/Contamination related by products.
bruce
 
quote:

Originally posted by bruce381:
To Me there is At least this:

Coke...Hard solid "dry" dirt like baked on
Sludge...Greasey thick stick goo.
Varnish...Baked on thin hard or sticky coating

I think that ALL are Oxidation/Contamination related by products.
bruce


That's the way I'd heard it....
 
Sludge will occur when the oils add pack can no longer hold add/or neutralize the contaminants produced by combustion and oil breakdown. Engines whose components are opererating within a desired temp range will produce less contamination. Proper add packs and base oils will produce less contamination. I am sure this doesn't cover it all but it is all I can personally remember.
 
So, what's some of the better products OTC to remove the sludge, varnish, etc...?
 
TurboJim (or others):

You mean the good 'ol "shake the PCV and if it rattles well" it's fine is not a good way to evaluate it...?
dunno.gif


Can you inform us on any info. or data you may have on this...?

What's a better way to evaluate it or what frequency should it be changed...?
dunno.gif


Let us know !!

Thanks,

cheers.gif
 
First off, observe/obey a very conservative OCI (4~6Kmiles typical). For some cars/engine designs, go with 4K

Second: unless it's a metered orifice type of PCV valving (Honda 7th gen civic 1.7L engine), otherwise, all checkvalve type PCV valve, simply toss it away and get a new one every 2 years, irregardless of mileage, and get a factory replacement (no aftermarket plse).

I personally would not care about keeping a PCV valve over an extended period of time unless I can assure myself that I'm providing a proper operational environment for it. And if you think by skimping on PCV valving replacement intervals, think again (esp. places where air-care/emissions testing are a must).

If you like to know what a good PCV valve should "sound", do this:

buy a new factory unit and keep it in the plastic bag. Take the old one off and then shake it and compared the sound of the one off your engine vs the one you bought. If you don't hear a clear, well-defined rattle or it takes too much effort to make it rattle then well, it's time to replace it.

and if these instructions aren't clear enough, might as well change the PCV valve on a regular basis and then forget about the rest.

As for engine sludge cleaning, AutoRx gets my vote. Most of the OTC cleaners we fould here are literally useless and frankly I don't waste my hard-earned $$ on it.
 
Quest,

Sounds good - I haven't found too good of an OTC cleaner...

Brian,

Yes - just been there. Sometimes it's nice to have someone list what worked best for them in a forum like this, especially for noobies, so they don't have to search around for it...
 
After changing out the the PVC valve for the very first time in my V6 '89 Toyota truck all of the oil leaks I had immediatly stopped. At that point I was half way through the rinse phase on a 3rd AutoRx treatment. At the same time I changed out a valve cover gasket and observed there was a significant amount of sludge/varnish that AutoRx had yet to remove. I don't know what things looked like before I started the treatments on that side. I had changed out the other valve cover gasket a few years back and saw no evidence of sludge at that time. That valve cover has a breather tube which feeds back into the air stream just ahead of the throttle body, so flow is not restricted. My normal OCI is every 3,000 miles by the way.

It's been my observation that if I pull a valve cover gasket on an engine I'm more likely to see sludge/varnish build up on those who's PVC valve have never been changed out.

I have no doubt that AutoRx has the ability to remove sludge/varnish off of engine parts. But it cannot overcome the effects of a warn or defective PVC valve.
 
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